/Engine/Source/Runtime/AssetRegistry/Public/AssetRegistry/IAssetRegistry.h
Gets a list of PackageNames that reference the supplied package. (On disk references ONLY)
bool GetReferencers ( [FName](API\Runtime\Core\UObject\FName) PackageName, [TArray](API\Runtime\Core\Containers\TArray)< [FName](API\Runtime\Core\UObject\FName) > & OutReferencers, [UE::AssetRegistry::EDependencyCategory](API\Runtime\CoreUObject\Misc\UE__AssetRegistry__EDependencyCa-) Category, const [UE::AssetRegistry::FDependencyQuery](API\Runtime\CoreUObject\Misc\FDependencyQuery) & Flags ) const